Shovel, monitoring device of the same and output device of shovel

ABSTRACT

A temporary storage device temporarily stores image data acquired by an imaging device. Each of a plurality of sensors detects a plurality of physical quantities relating to an operation state of a shovel. A control device performs an operation abnormality determination based on detection values detected by the sensors. When an operation is determined to be abnormal, the control device transmits the image data, which corresponds to a period from a first time prior to a time at which the operation is determined to be abnormal to at least the time at which the operation is determined to be abnormal, from the temporary storage device to the abnormality information storage device. Therefore, it is easy to specify a cause of abnormality of the operation state of the shovel.

TECHNICAL FIELD

The present invention relates to a shovel capable of determining an operational abnormality, a monitoring device of the shovel, and an output device mounted on a shovel capable of determining an operational abnormality.

BACKGROUND ART

A failure determination method for construction equipment, based on a detection value detected by a sensor mounted on the construction equipment, has been known (see PTL 1). Failure information is sent to a center, and therefore a failure diagnosis procedure is extracted in the center, based on the sensor detecting an abnormal value. An operator of the construction equipment conducts a failure diagnosis in accordance with the failure diagnosis procedure.

PRIOR ART DOCUMENT Patent Literature

[PTL 1] Japanese Unexamined Patent Application Publication No. 2002-332664

SUMMARY OF INVENTION Problems to be Solved by Invention

In some cases, it is difficult to specify the cause of failure only by performing a diagnosis based on the detection value of the sensor and following the failure diagnosis procedure even when the failure diagnosis procedure is provided. Particularly, an attachment, such as a boom, and a cabin are mounted on a revolving superstructure of a shovel. Thus, motion not only in a front-rear direction but also in a right-left direction is carried out in the shovel. Since a working range of the shovel is extensive as described above, a situation in which the shovel encounters failure is likely to occur. An object of the invention is to provide a shovel which enables an operator to easily specify the cause of failure by making the operator confirm the circumstances at the time of failure and a monitoring device of the shovel.

Means of Solving Problems

According to an aspect of the invention, there is provided a shovel including:

an imaging device;

a temporary storage device that temporarily stores image data acquired by the imaging device;

a plurality of sensors that each detect a plurality of physical quantities relating to an operation state of the shovel;

an abnormality information storage device; and

a control device that performs an operation abnormality determination based on a detection value detected by the sensors and causes the image data, which corresponds to a period from a first time prior to a time at which an operation is determined to be abnormal to at least the time at which the operation is determined to be abnormal, to be transmitted from the temporary storage device to the abnormality information storage device when the operation is determined to be abnormal.

According to another aspect of the invention, there is provided a shovel including:

an imaging device;

a temporary storage device that temporarily stores image data acquired by the imaging device;

a plurality of sensors that each detect a plurality of physical quantities relating to an operation state of the shovel;

a transmitter for transmitting the data, and

a control device that performs an operation abnormality determination based on a detection value detected by the sensors and causes the image data stored in the temporary storage device, which corresponds to a period from a first time prior to a time at which an operation is determined to be abnormal to at least the time at which the operation is determined to be abnormal, to be transmitted from the transmitter when the operation is determined to be abnormal.

According to still another aspect of the invention, there is provided a monitoring device of a shovel including:

a transceiver that receives a plurality of detection values detected by a sensor for detecting a plurality physical quantities relating to an operation state of the shovel and image data acquired by an imaging device installed on the shovel and transmits a command to the shovel;

an abnormality information storage device; and

a control device,

wherein the control device performs an operation abnormality determination based on the detection values which are detected by the sensor and input from the transceiver and causes a command instructing transmission of image data, which corresponds to a period from a first time prior to a time at which an operation is determined to be abnormal to at least the time at which the operation is determined to be abnormal, to be transmitted to the shovel via the transceiver when the operation is determined to be abnormal, and

wherein the image data which is transmitted from the shovel to the transceiver is stored in the abnormality information storage device in response to the command.

Advantageous Effects of Invention

It is possible to investigate the cause of abnormality using image data at the time where an operation state is determined to be abnormal.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1A and FIG. 1B are a side view and a plan view, respectively, of a shovel according to an embodiment 1.

FIG. 2 is a block diagram of the shovel according to the embodiment 1.

FIG. 3 is a flowchart showing a process of an image capture control device of the shovel according to the embodiment 1.

FIG. 4 is a flowchart showing a process of a control device of the shovel according to the embodiment 1.

FIG. 5 is a view showing an example of an image displayed on an output device of the shovel according to the embodiment 1.

FIG. 6 is a flowchart showing a process of a control device of a shovel according to an embodiment 2.

FIG. 7 is a chart showing an example of a detection value detected by a sensor.

FIG. 8 is a view showing an example of an image displayed on an output device of the shovel according to the embodiment 2.

FIG. 9 is a block diagram of a shovel and a monitoring device according to an embodiment 3.

FIG. 10 is a flowchart showing a process of a control device of the shovel according to the embodiment 3.

FIG. 11 is a block diagram of a shovel and a monitoring device according to an embodiment 4.

FIG. 12 is a flowchart showing a process of a control device of the monitoring device according to the embodiment 4.

DESCRIPTION OF EMBODIMENTS Embodiment 1

FIG. 1A and FIG. 1B are a side view and a plan view, respectively, of a shovel according to an embodiment 1. A hydraulic shovel exemplifies a shovel, in the embodiment 1. However, the embodiment 1 can be adopted to other shovels, such as a hybrid shovel or an electric shovel.

An upper revolving superstructure 12 is mounted to an undercarriage 10 via a revolving bearing 11. The upper revolving superstructure 12 revolves clockwise or counter-clockwise with respect to the undercarriage 10. A boom 13 is installed on the upper revolving superstructure 12. An arm 15 is connected to a tip of the boom 13. A bucket 17 is connected to a tip of the arm 15. The boom 13 is driven by a hydraulic cylinder 14. The arm is driven by a hydraulic cylinder 16. The bucket 17 is driven by a hydraulic cylinder 18. Furthermore, a cabin 19 is mounted to the upper revolving superstructure 12, and a driver gets into the cabin 19 and operates a hydraulic shovel.

An imaging device 20 is mounted to the upper revolving superstructure 12. A frontward imaging device 20F, a right imaging device 20R, a left imaging device 20L and a backward imaging device 20B constitute the imaging device 20. The frontward imaging device 20F, the right imaging device 20R, the left imaging device 20L and the backward imaging device 20B respectively image front, right, left and back sides of the upper revolving superstructure 12. The frontward imaging device 20F is mounted between the cabin 19 and the boom 13, for example. An omnidirectional image can be obtained by combining images obtained by these imaging devices.

FIG. 2 shows a block diagram of an abnormality determination function of the shovel. An image capture control device 24 stores image data acquired by the imaging device 20 in a temporary storage device 25 at a predetermined cycle. The temporary storage device 25 has a ring buffer structure, for example. In other words, the oldest image data are overwritten (replaced) with new image data when no free storage area remains.

Information that specifies a capturing method of the image data, such as resolution and a capturing cycle, is stored in an image capture mode storage portion 26. A parameter for specifying the resolution is set to any one of a “high resolution”, a “normal resolution” and a “low resolution”, for example. A parameter for specifying the capturing cycle is set to any one of a “long cycle”, a “normal cycle” and a “short cycle”. An image capture mode is determined by the resolution and the capturing cycle. An operator operates an input device 33 to input the image capture mode to a control device 30. Then, the image capture mode is set to the image capture mode storage portion 26. An image capture cycle is about several hundred ms to 1 sec, for example.

The image capture control device 24 stores image data acquired by the imaging device 20, based on the image capture mode set to the image capture mode storage portion 26, in the temporary storage device 25. By decreasing image resolution or lengthening the capturing cycle, it is possible to store a long term image data in the temporary storage device 25. On the contrary, by increasing the image resolution and shortening the capturing cycle, it is possible to increase an information amount of image data in a predetermined time.

A plurality of sensors 34 are installed on the shovel. The sensors 34 detect physical quantities relating to an operation state of the shovel. An engine speed, a radiator coolant temperature, a fuel temperature, an atmospheric pressure, an engine oil pressure, a boost temperature, an intake temperature, a hydraulic operating fluid temperature, a boost pressure, a battery voltage, a hydraulic pressure of each part, a machine operation time, a traveling operation time, a revolving operation time, an idle time and the like are exemplified as the physical quantities relating to the operation state.

The control device 30 controls the temporary storage device 25, the image capture mode storage portion 26, an output device 31, and an abnormality information storage device 32.

Instructions of an operator are input to the control device 30 via the input device 33. The detection values detected by the sensors 34 are input to the control device 30. A liquid crystal display device is adopted as the output device 31, for example. A touch-panel type liquid crystal display device maybe adopted as a device functioning as the output device 31 and the input device 33.

FIG. 3 shows a flowchart of an operation of the image capture control device 24. When an engine start key of the shovel is turned on, the image data is acquired from the imaging device 20 in step SA1. The resolution of the image data is converted so as to be the resolution specified in the image capture mode, and then the converted image data is stored in the temporary storage device 25. When a free area for storing the image data does not remain, the oldest image data are overwritten with new image data.

In step SA2, a period of a capturing cycle specified in the image capture mode elapses. Then, whether or not the start key of the shovel is in a stopped state is determined in step SA3. When the start key of the shovel is in a stopped state, the process is finished. When the start key of the shovel is not in a stopped state, the process returns to step SA1.

FIG. 4 shows a flowchart of an operation of the control device 30. When the engine start key of the shovel is turned on, the detection values detected by the sensors 34 are acquired in step SB1. Whether or not the acquired detection values are within an allowable range is determined in step SB2. The allowable range is preset for each physical quantity relating to the operation state.

Whether or not the operation state is abnormal is determined in step SB3. When at least one of the detection values is out of the allowable range, the operation state of the shovel is determined to be abnormal. When all the detection values are within the allowable range, the operation state is determined to be normal. When the operation state is determined to be normal, whether or not the shovel is in a stopped state is determined in step SB5. When the operation state is determined to be abnormal, step SB4 is executed. Then, whether or not the shovel is in a stopped state is determined in step SB5.

Hereinafter, a process of step SB4 will be described. Among the image data stored in the temporary storage device 25, the image data which corresponds to a period from a first time prior to a time at which the operation is determined to be abnormal to the present is read out and stored in the abnormality information storage device 32. Furthermore, the detection value of each sensor 34 at the time when the operation is determined to be abnormal is stored in the abnormality information storage device 32. The stored image data and the detection value of the sensor 34 are associated with each other. The image data and the detection value of the sensor 34 may be associated with each other, based on indices given thereto, for example. In addition, the image data and the detection value of the sensor 34 may be associated with each other, based on the time at which the data is acquired.

Furthermore, in addition to the image data corresponding to a period prior to the time at which the operation is determined to be abnormal, image data corresponding to a period after that time may be stored in the abnormality information storage device 32. At a second time following the time at which the operation is determined to be abnormal, the image data corresponding to a period from the first time to the second time may be transmitted from the temporary storage device 25 to the abnormality information storage device 32 after waiting for the image data transmission until the second time, for example. A period from the first time to the time at which the operation is determined to be abnormal is set to about 30 sec to 5 min, and a period from the time at which the operation is determined to be abnormal to the second time is set to about 10 sec to 1 min.

Furthermore, an alarm may be raised from the output device 31 to inform an operator that the operation state is abnormal.

When, in step SB5, it is determined that the shovel is in a stopped state, the process is finished. When it is determined that the shovel is not in a stopped state, the process returns to step SB1 after a predetermined time elapses in step SB6. The waiting time of step SB6 is set to several hundred ms to 1 sec, for example.

In the embodiment 1, the image data corresponding to a period before the time at which the operation is determined to be abnormal or a period before and after the time is stored in the abnormality information storage device 32. The image data is useful in specifying the cause of abnormality. When any abnormality occurs in the shovel, it is possible for a maintenance person to search for the cause of the abnormality by operating the input device 33 (see FIG. 2).

FIG. 5 is a view showing an example of an image displayed on the output device 31 at the time of searching for the cause of abnormality. An image display window 35, a progress status bar 36, operating icons 37 and a character information display window 38 are shown in a display screen. A display screen when it is determined that an abnormality has occurred at the time of 10:35:20 on Apr. 26, 2012 is exemplarily shown in FIG. 5.

The progress status bar 36 shows a period from a data collection start time of the image data stored in the abnormality information storage device 32 (see FIG. 2) to a finish time. When a slider 36A displayed in the progress status bar 36 is slid, an image at the time corresponding to the position of the slider 36A is displayed on the image display window 35. A mark 36B for indicating abnormality occurrence time is displayed on the progress status bar 36 at the position corresponding to a time of abnormality occurrence. The progress status bar 36 and the slider 36A function as a time indicator by which the time of the image to be displayed on the image display window 35 is indicated. The length of the progress status bar 36 corresponds to a time range within which the time can be specified by the slider 36A. A numeric input window used for inputting a time as a numeric value maybe displayed as a time indicator, instead of the slider 36A.

A playback, a frame-by-frame playback, a pause or the like of moving image can be carried out by operating the operating icon 37. In addition, the operating icon 37 includes an instruction button used for jumping to the time of abnormality occurrence. When the instruction button is operated, the image at the time when the operation is determined to be abnormal in step SB2 shown in FIG. 4 is displayed on the image display window 35. It is possible to quickly display the image at the time immediately before the time of abnormality occurrence, by providing the instruction button used for jumping to the time of abnormality occurrence.

FIG. 5 shows an example of an image at the time when the hydraulic abnormality is detected. It is possible to know that a truck intrudes between the upper revolving superstructure 12 and the bucket 17 (see FIGS. 1A and 1B), from the image shown in FIG. 5. Here, the following estimation can be carried out. The truck is in contact with hydraulic piping, and thus the hydraulic piping is broken. Therefore, a hydraulic abnormality is detected. In this way, it is possible to specify the cause of the abnormality by inspecting the image data corresponding to a period before and after the time at which the abnormality occurs.

Embodiment 2

A functional block diagram of a shovel according to an embodiment 2 is the same as the functional block diagram of the shovel according to the embodiment 1 shown in FIG. 2.

FIG. 6 is a flowchart showing an operation of the control device 30 (see FIG. 2) of the shovel according to the embodiment 2. The control device 30 of the shovel according to the embodiment 2 includes a unit space defining flag and an area for storing the inverse matrix of a correlation matrix.

The detection value is acquired from the sensor 34 (see FIG. 2), in step SC1. Whether or not the unit space is defined is determined in step SC2. Specifically, it is determined whether the unit space defining flag is set to “defined” or “undefined”, in step SC2. The unit space is used as a reference for determination when the abnormality determination using Mahalanobis-Taguchi method is carried out in the following step. When the unit space is undefined, the detection value of the sensor 34 is accumulated as a sample, in step SC3. Whether or not the number of accumulated samples is enough is determined in step SC4. When the number of samples is enough, the unit space is defined in step SC5. Specifically, the correlation matrix of physical quantities of samples which constitute the unit space and the inverse matrix of the correlation matrix are calculated.

Hereinafter, a method of defining the unit space will be described.

FIG. 7 shows an example of the detection values detected by the sensor 34. The number of physical quantities of a detection target is represented by K, and the number of accumulated samples is represented by N. The detection values of N samples constitute the unit space. In a sample to which the sample number n is assigned, the detection value of a physical quantity k is indicated as x (n, k). The mean value and the standard deviation are calculated with respect to the detection values of each physical quantity. The mean value and the standard deviation of the physical quantity k are indicated as m(k) and a(k), respectively.

The detection values of each sample are standardized, whereby standardized detection values are calculated. The standardized detection value X(n,k) of the detection value x(n,k) of the physical quantity k in the sample to which the sample number n is assigned is shown as the following Equation.

$\begin{matrix} {{X\left( {n,k} \right)} = \frac{{x\left( {n,k} \right)} - {m(k)}}{\sigma (k)}} & \left\lbrack {{Equation}\mspace{14mu} 1} \right\rbrack \end{matrix}$

Correlation coefficients between the physical quantities are calculated based on the standardized detection values X (n,k).

A correlation coefficient r(i,j) of a physical quantity i and a physical quantity j is calculated by the following Equation.

$\begin{matrix} {{r\left( {i,j} \right)} = {\frac{1}{N}{\sum\limits_{l = 1}^{N}\; {{X\left( {l,i} \right)}{X\left( {l,j} \right)}}}}} & \left\lbrack {{Equation}\mspace{14mu} 2} \right\rbrack \end{matrix}$

A correlation matrix R of the physical quantities 1 to K is shown as the following Equation.

$\begin{matrix} {R = \begin{pmatrix} 1 & {r\left( {1,2} \right)} & \ldots & {r\left( {1,K} \right)} \\ {r\left( {2,1} \right)} & 1 & \ldots & {r\left( {2,K} \right)} \\ \vdots & \vdots & \ddots & \vdots \\ {r\left( {K,1} \right)} & {r\left( {K,2} \right)} & \ldots & {r\left( {K,K} \right)} \end{pmatrix}} & \left\lbrack {{Equation}\mspace{14mu} 3} \right\rbrack \end{matrix}$

An inverse matrix A of the correlation matrix R is calculated. The inverse matrix A is stored in the control device 30 so as to be available in the following step.

In step SC6, the unit space defining flag is set to “defined”. In the case where the number of samples is determined to be not enough in step SC4, or after the unit space defining flag is set to “defined” in step SC6, the process waits for a predetermined time in step SC11. The waiting time is set to about several hundred ms to 1 sec, for example. After waiting for the predetermined time, the process returns to step SC1.

Furthermore, the unit space defining flag can be reset by the operation of an operator. In other words, it is possible to set the unit space defining flag to “undefined”.

When, in step SC2, the unit space is determined to be defined, a Mahalanobis distance (MD) of the detection values (verification data) detected by each sensor 34 is calculated in step SC7. Hereinafter, a calculation method of the Mahalanobis distance will be described.

The value of a physical quantity k, out of K detection values (verification data) detected by the sensors 34, is indicated as y(k). The detection value y(k) is standardized, whereby a standardized detection value Y (k) is calculated. The standardized detection value Y(k) can be calculated by the following Equation.

$\begin{matrix} {{Y(k)} = \frac{{y(k)} - {m(k)}}{\sigma (k)}} & \left\lbrack {{Equation}\mspace{14mu} 4} \right\rbrack \end{matrix}$

The square (D²) of the Mahalanobis distance of the verification data can be calculated by the following Equation using the inverse matrix A of the correlation matrix R.

$\begin{matrix} {D^{2} = {\frac{1}{K}\begin{pmatrix} {Y(1)} & {Y(2)} & \ldots & {Y(K)} \end{pmatrix}{A\begin{pmatrix} {Y(1)} \\ {Y(2)} \\ \vdots \\ {Y(K)} \end{pmatrix}}}} & \left\lbrack {{Equation}\mspace{14mu} 5} \right\rbrack \end{matrix}$

When the Mahalanobis distance MD (or the square D² of the Mahalanobis distance) is calculated, the Mahalanobis distance MD and a threshold are compared in step SC8. The threshold is set in advance. The threshold is set to 2, for example. When the threshold is compared to the square D² itself of the Mahalanobis distance defined in Equation described above, the threshold is set to 2²=4. When the Mahalanobis distance MD is greater than the threshold, the process of step SC9 is to start. The process of step SC9 is the same as the process of step SB4 (see FIG. 4) in the embodiment 1.

When the process of step SC9 is finished or when the Mahalanobis distance MD is determined, in step SC8, to be equal to or less than the threshold, whether or not the shovel is in the stopped state is determined in step SC10. When the shovel is in the stopped state, the process is finished. When the shovel is not in the stopped state, the process waits for a predetermined time in step SC11. Then, the process returns to step SC1.

In the embodiment 2, the Mahalanobis-Taguchi method is adopted as a method of determining whether or not an operation state is abnormal. Thus, it is unnecessary to set the allowable range to each detection value of the sensors 34.

In the embodiment 1 described above, the allowable range of the detection value is set based on cases where the abnormality occurred in the past or the like, for example. Thus, there is a possibility that a new abnormality which has not occurred in the past may not be detected in some cases. However, by adopting the Mahalanobis-Taguchi method, it is unnecessary to set the allowable range of the detection value based on cases in the past. Therefore, it is possible to detect a new abnormality which has not occurred in the past.

Furthermore, deviation amounts of the plurality of detection values with respect to allowed values are integrated into the Mahalanobis distance (MD) in the embodiment 2, and thus it is possible to easily determine whether or not the operation is abnormal.

FIG. 8 shows an example of an image displayed on the output device 31 (see FIG. 2) when the cause of abnormality is searched for in the shovel according to the embodiment 2. Hereinafter, differences between the embodiment 2 and the embodiment 1 shown in FIG. 5 will be described. Besides the image display window 35, the progress status bar 36, the operating icon 37 and the character information display window 38, a window 39 for displaying an alarm level variation is shown in the embodiment 2. A variation graph of alarm levels with the elapsed time corresponding to a time range specified by the slider 36A is displayed in the window 39 for displaying the alarm level variation. A display image time line 39A is displayed in the window 39 for displaying alarm level variation at a position corresponding to the time (the time corresponding to the displayed image) specified by the slider 36A. Furthermore, an abnormality occurrence time line 39B is displayed in the window 39 for displaying the alarm level variation at a position corresponding to the mark 36B for indicating abnormality occurrence time. The alarm level shows the level of possibility that an abnormality is occurring in the shovel. The Mahalanobis distance calculated in step SC7 (see FIG. 6) is adopted as the alarm level. It is conceived that any cause of abnormality is generated immediately before the alarm level is increased rapidly.

Embodiment 3

FIG. 9 shows a functional block diagram of a shovel and a monitoring device according to an embodiment 3. Hereinafter, a description focuses on differences between the shovel of the embodiment 3 and the shovel of the embodiment 1. A description of the same configuration will not be repeated.

In the embodiment 1, an abnormality determination process and the accumulation process of data when the abnormality occurs are completed only in the shovel. In the embodiment 2, the abnormality determination process is carried out by the local control device 30 mounted on a shovel 50. The image data and the like when the operation is determined to be abnormal are accumulated in a monitoring device 60. A transceiver 40 which transmits various data, such as image data, to the monitoring device 60 via a communication line 45 is mounted on the shovel 50.

A transceiver 41, a control device 61, an output device 62, an input device 63 and the abnormality information storage device 32 are provided in the monitoring device 60. The transceiver 41 receives data sent from the shovel 50 via the communication line 45. The control device 61 controls the output device 62, the input device 63 and the abnormality information storage device 32.

FIG. 10 shows a flowchart of a process performed by the local control device 30 mounted on the shovel 50. Steps SB1, SB2, SB3, SB5, and SB6 are, respectively, the same as steps SB1, SB2, SB3, SB5, and SB6 of the embodiment 1 shown in FIG. 4. The process of step SD4 is executed instead of step SB4 in the embodiment 1. Hereinafter, step SD4 will be described.

When the operation state is determined, in step SB3, to be abnormal, the local control device 30 waits until the second time following the determination time such that image data is accumulated in the temporary storage device 25. The image data corresponding to a period from the first time prior to a time at which the operation is determined to be abnormal to the second time, out of the image data stored in the temporary storage device 25, and the detection values of the sensors 34 when the operation is determined to be abnormal are transmitted from the transceiver 40 to the monitoring device 60. Instead, the image data corresponding to a period from the first time prior to the time at which the operation is determined to be abnormal to the time at which the operation is determined to be abnormal, out of the image data stored in the temporary storage device 25, may be transmitted. Furthermore, an alarm is raised from the output device 31, whereby the abnormality is notified to an operator.

Subsequently, a process of the control device 61 of the monitoring device 60 will be described. When the image data corresponding to a period before and after the time at which the operation state is determined to be abnormal and the detection values of the sensors are received from the shovel 50, the control device 61 stores the received image data in the abnormality information storage device 32. At the same time, an alarm is raised from the output device 62.

When an observer of the monitoring device 60 commands a data display via the input device 63, the control device 61 outputs the detection values of the sensor and the image data, which are accumulated in the abnormality information storage device 32, to the output device 62. The image data corresponding to a period before and after the time at which the operation is determined to be abnormal becomes useful information when an observer specifies the cause of abnormality. The image displayed on the output device 62 is the same as the image output on the output device 31 according to the embodiment 1 shown in

FIG. 5 or the image output on the output device 31 according to the embodiment 2 shown in FIG. 8.

Embodiment 4

FIG. 11 is a functional block diagram of a shovel and a monitoring device according to an embodiment 4. Hereinafter, a description focuses on differences of the shovel and the monitoring device between the embodiment 4 and the embodiment 3. A description of the same configuration will not be repeated.

The local control device 30 mounted on the shovel 50 carries out the abnormality determination process in the embodiment 3. However, the control device 61 mounted on the monitoring device 60 carries out the abnormality determination process in the embodiment 4. The shovel 50 transmits an abnormality determination request as well as the detection values of the sensor 34 to the monitoring device 60 at predetermined cycles.

FIG. 12 shows a flowchart of a process performed by the control device 61 of the monitoring device 60. Whether or not the abnormality determination request is received from the shovel 50 is determined in step SE1. When the abnormality determination request is not received, step SE1 is repeated until the abnormality determination request is received.

When the abnormality determination request is received, the abnormality determination is performed in step SE2, based on the detection value of the sensor which is received from the shovel 50. The abnormality determination process is the same as the abnormality determination process of steps SB2 and SB3 (see FIG. 4) according to the embodiment 1 or steps SC7 and SC8 (see FIG. 6) according to the embodiment 2.

When the operation state is determined to be abnormal in step SE3, it is commanded, in step SE4, that shovel 50 transmits the image data. This command includes a start time (the first time) and a finish time (the second time) of the image data to be transmitted. When receiving the transmission command of the image data, the shovel 50 transmits the image data corresponding to a period from the first time to the second time, out of the image data accumulated in the temporary storage device 25, to the monitoring device 60 as a response to the command. In addition, it is preferable to perform a data compression of the image data before transmission.

In step SE5, the image data received from the shovel 50 and the detection values of the sensor at the time when the operation is determined to be abnormal are stored in the abnormality information storage device 32 in a state of being associated with each other. When a process of step SE5 is finished, whether or not the operation of the monitoring device 60 is in a stopped state is determined in step SE6. Whether or not the operation of the monitoring device 60 is in a stopped state is determined in step SE6, even when the operation is determined, in step SE3, not to be abnormal.

When the monitoring device 60 is determined, in step SE6, not to be in a stopped state, the process returns to step SE1. When the monitoring device 60 is determined to be in a stopped state, the process is finished.

To specify the cause of the abnormality, an observer of the monitoring device 60 can use the image corresponding to a period before and after the time of the detected abnormality which is displayed on the output device 62, even in the case of the embodiment 4. The image displayed on the output device 62 is the same as the image output on the output device 31, according to the embodiment 1 shown in FIG. 5, or the image output on the output device 31, according to the embodiment 2 shown in FIG. 8.

Although the invention is described with reference to the embodiments described above, it is not limited thereto. For example, it is apparent to those skilled in the art that the invention can be modified, improved, combined, or the like in various ways.

REFERENCE SIGNS LIST

-   10: undercarriage -   11: revolving mechanism -   12: upper revolving superstructure -   13: boom -   14: hydraulic cylinder -   15: arm -   16: hydraulic cylinder -   17: bucket -   18: hydraulic cylinder -   19: cabin -   20F: frontward imaging device -   20R: right imaging device -   20L: left imaging device -   20B: backward imaging device -   24: image control device -   25: temporary storage device -   26: operation mode storage portion -   27: sensor -   30: control device -   31: output device -   32: abnormality information storage device -   33: input device -   34: sensor -   35: image display window -   36: progress status bar -   36A: slider -   36B: mark for indicating abnormality occurrence time -   37: operating icon -   38: character information display window -   39: window for displaying alarm level variation -   39A: display image time line -   39B: abnormality occurrence time line -   40, 41: transceiver -   45: communication line -   50: shovel -   60: monitoring device -   61: control device -   62: output device -   63: input device 

1. A shovel comprising: an imaging device; a temporary storage device that temporarily stores image data acquired by the imaging device; a plurality of sensors that each detect a plurality of physical quantities relating to an operation state of the shovel; an abnormality information storage device; and a control device that determines whether or not an operation is abnormal based on detection values detected by the sensors, and transmits the image data, which corresponds to a period from a first time prior to a time at which the operation is determined to be abnormal to at least the time at which the operation is determined to be abnormal, from the temporary storage device to the abnormality information storage device when the operation is determined to be abnormal.
 2. The shovel according to claim 1, wherein the control device stores the detection values detected by the sensors as well as the image data at the time at which the operation is determined to be abnormal in the abnormality information storage device.
 3. The shovel according to claim 1, wherein the control device additionally transmits the image data, which corresponds to a period until a second time following the time at which the operation is determined to be abnormal, from the temporary storage device to the abnormality information storage device when the operation is determined to be abnormal.
 4. The shovel according to claim 1, wherein the control device acquires the detection values detected by the plurality of sensors, during a normal operation, and decides an unit space, which is used in Mahalanobis-Taguchi method, based on the acquired detection values, calculates Mahalanobis distance from the center of the unit space to detection values of an evaluation-target detected by the plurality of sensors, and performs the operation abnormality determination based on the calculated Mahalanobis distance.
 5. The shovel according to claim 1, wherein the temporary storage device has a ring buffer structure where the oldest image data are overwritten with new image data when no free storage area remains, wherein the control device has an image capture mode storage portion for storing an image capture mode which specifies the resolution of image data to be stored in the temporary storage device, and wherein the image data which is acquired by the imaging device is stored in the temporary storage device at the resolution specified in the image capture mode stored in the image capture mode storage portion.
 6. The shovel according to claim 1, further comprising: an output device for displaying an image, wherein the control device displays a time indicator for an operator to specify a time on the output device, and displays the image data at the time specified by the time indicator, out of the image data stored in the abnormality information storage device, on the output device as an image.
 7. The shovel according to claim 6, wherein the control device displays information about the time range within which a time can be specified to be displayed on the time indicator and displays a temporal variation of alarm levels on the output device, corresponding to the time range displayed on the time indicator.
 8. A shovel comprising: an imaging device; a temporary storage device that temporarily stores image data acquired by the imaging device; a plurality of sensors that each detect a plurality of physical quantities relating to an operation state of the shovel; a transmitter for transmitting the data, and a control device that performs an operation abnormality determination based on detection values detected by the sensors, and transmits the image data stored in the temporary storage device, which corresponds to a period from a first time prior to a time at which an operation is determined to be abnormal to at least the time at which the operation is determined to be abnormal, from the transmitter when the operation is determined to be abnormal.
 9. The shovel according to claim 8, wherein the control device transmits the detection values detected by the sensors at the time at which the operation is determined to be abnormal as well as the image data from the transmitter.
 10. The shovel according to claim 8, wherein the control device additionally transmits the image data, which corresponds to a period until a second time following the time at which the operation is determined to be abnormal, from the transmitter when the operation is determined to be abnormal.
 11. The shovel according to claim 8, wherein the control device acquires the detection values detected by the plurality of sensors, during a normal operation, and decides an unit space which is used in Mahalanobis-Taguchi method, based on the acquired detection values, calculates a Mahalanobis distance from the center of the unit space to detection values of an evaluation-target acquired by the plurality of sensors, and performs the operation abnormality determination of an operation based on the calculated Mahalanobis distance.
 12. A monitoring device of a shovel, comprising: a transceiver that receives a plurality of detection values detected by sensors for detecting a plurality of physical quantities relating to an operation state of the shovel and image data acquired by an imaging device installed on the shovel and transmits a command to the shovel; an abnormality information storage device; and a control device, wherein the control device determines whether or not an operation is abnormal based on the detection values which are detected by the sensors and input from the transceiver, and the control device transmits a command instructing transmission of image data, which corresponds to a period from a first time prior to a time at which the operation is determined to be abnormal to at least the time at which the operation is determined to be abnormal, to the shovel via the transceiver when the operation is determined to be abnormal, and wherein the control device stores the image data which is transmitted from the shovel to the transceiver in the abnormality information storage device in response to the command.
 13. The monitoring device of a shovel according to claim 12, further comprising: an output device for displaying an image, wherein the control device displays a time indicator for an operator to specify a time on the output device, and displays the image data at the time specified by the time indicator, out of the image data stored in the abnormality information storage device, on the output device as an image.
 14. The monitoring device of a shovel according to claim 13, wherein the control device displays information about the time range within which a time can be specified on the time indicator and displays a temporal variation of alarm levels on the output device, corresponding to the time range displayed on the time indicator.
 15. A monitoring device of a shovel comprising: a receiver that receives image data from a shovel that has an imaging device, a temporary storage device temporarily storing image data acquired by the imaging device, a plurality of sensors that each detect a plurality of physical quantities relating to an operation state of the shovel, and a local control device that performs an operation abnormality determination based on detection values detected by the sensors, reads out the image data from the temporary storage device when the operation is determined to be abnormal, and transmits the image data to the monitoring device of the shovel; an abnormality information storage device for storing image data; an output device for displaying an image; and a control device, wherein the control device stores the image data received by the receiver in the abnormality information storage device and displays the image data stored in the abnormality information storage device on the output device as an image.
 16. The monitoring device of a shovel according to claim 15, wherein the control device displays a time indicator for an operator to specify a time on the output device, and displays the image data at the time specified by the time indicator, out of the image data stored in the abnormality information storage device, on the output device as an image.
 17. An output device of a shovel that displays image data acquired by an imaging device mounted on a shovel, wherein the image data, which corresponds to a period from a first time prior to a time at which the shovel is determined to be abnormal to at least the time at which the shovel is determined to be abnormal, is displayed.
 18. A method of monitoring a shovel, comprising: storing image data acquired by an imaging device mounted on a shovel in a temporary storage device temporarily; detecting a plurality of physical quantities relating to an operation state of the shovel by a plurality of sensors mounted on the shovel, respectively, and performing an operation abnormality determination based on detection values detected by the sensors; reading out the image data from the temporary storage device and transmitting the image data to the monitoring device of the shovel when an operation is determined to be abnormal in performing an operation abnormality determination; storing the image data received by the monitoring device in an abnormality information storage device of the monitoring device; and displaying the image data stored in the abnormality information storage device as an image on an output device of the monitoring device.
 19. The method of monitoring the shovel according to claim 18, further comprising: displaying a time indicator for an operator to specify a time on the output device; and specifying a time on the time indicator by an operator, wherein the image data at the time specified by an operator, out of the image data stored in the abnormality information storage device, is displayed as an image on the output device in displaying the image data as an image on the output device.
 20. A method of monitoring a shovel, comprising: acquiring image data acquired by an imaging device mounted on a shovel; and displaying the image data, which corresponds to a period from a first time prior to a time at which the shovel is determined to be abnormal to at least the time at which the shovel is determined to be abnormal, out of the image data acquired in the step of acquiring the image data, on an output device. 